• Journal of Dairy Science and Biotechnology
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• v.16 no.2
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• pp.98-105
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• 1998

Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides(CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These result suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• 한국유가공학회:학술대회논문집
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• 1998.05a
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• pp.22-29
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• 1998

Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides (CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These results suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.886-895
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• 2010

The level of fat and salt can affect the product quality and storage stability of processed meats. Additionally, consumers' demands require dietary guidelines for developing low-fat/salt functional foods. Microbial transglutaminase (MTGase), which enhances textural properties by catalyzing protein-protein cross-linkages, was introduced to develop healthier lowfat/salt meat products. The potential possibilities of low-fat/salt processed meats were reviewed under optimal conditions for functional ingredients from several previous studies. The addition of non-meat protein (e.g. sodium caseinate and soy protein isolates), hydrocolloids (e. g. konjac flour, carrageenan, and alginates), and MTGase alone or in combination with other functional ingredients improved textural and sensory properties similar to those of regularly processed meats. When MTGase was combined with hydrocolloids (konjac flour or sodium alginate) or other functional ingredients, gelling properties of meat protein were improved even at a low salt level. Based on these reviews, functional ingredients combined with new processing technologies could be incorporated into processed meats to improve the functionality of various low-fat/salt meat products.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.301-307
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• 2012

We investigated the effects of non-meat protein binders combined with glucono-${\delta}$-lactone (GdL) on the binding properties regarding restructured pork prepared by high-pressure treatment. Soy protein isolate (SPI), casein (CS), whey protein concentrate (WPC), and egg white (EW) were used as non-meat protein binders and compared with the control (no binder) and with the ${\kappa}$-carrageenan (KC) treatment. The compression and depression rates were 2.3 and 37 MPa/s, respectively, and pressurization was conducted at 200 MPa for 30 min at $4^{\circ}C$. After pressurization, the physical properties (pH, water-holding capacity, color, tensile strength, and microscopic structure) of the sample were evaluated. The combination of pressurization with acidification enabled cold-set meat binding, and the binding strength of restructured pork was enhanced by the addition of non-meat proteins. Among binders, SPI demonstrated the best efficiency in binding meat pieces. Therefore, the present study demonstrated that the combination of acidification and pressurization processes with the utilization of non-meat protein binders has a potential benefit in meat restructuring.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.89-98
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• 2014

In this study, soybean is used to produce soymilk according to various extracting methods and heating time. Specifically, the soy slurry is being filtered before being heated, or heated before being filtered. Following that the soymilk produced is freeze-dried to be powdered, and then, the quality characteristics of the powdered soymilk are mutually compared to determine the applicability of various food additives. The freeze-dried soymilk powder shows 2.03~6.35% of moisture content, and in terms of unit quantity, retained more proteins, which suggests that the ratio of protein extraction is higher than any other nutrients. Accordingly, the protein coefficient is significantly higher in soymilk powder being heated and processed than in raw soybeans. In particular, protein coefficient is the highest in the soymilk which is heated for 20 minutes before being filtered (SHBF20). The longer the heating time was, the trypsin inhibitor (TI) tended to be far less active. Such an inactivation seems to be more apparent in the "SHAF" soymilk powder than "SHBF" soymilk powder. Because protein had to be denaturated by heating for soymilk, the nitrogen solubility index (NSI) of soymilk powder is decreased considerably, while the protein digestibility, water absorption, emulsification and foaming activity all increase. Oil absorption tends to decrease slightly. As discussed above, the soymilk heated for 10 minutes after being filtered (SHAF10) and the soymilk heated for 20 minutes before being filtered (SHBF20) show optimum processing conditions for soymilk powder.

• Journal of fish pathology
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• v.19 no.1
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• pp.45-54
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• 2006

The immunogenicity of Edwardsiella tarda was surveyed under two different culture conditions. In SDS-PAGE patterns of the outer membrane proteins (OMPs) extracts of E. tarda, grown under Trypic soy broth (TSB) and TSB supplemented iron chelate 2,2‘-dipyridyl iron-restricted condition, were examined. The results showed that the iron-regulated outer membrane protein (IROMPs) with molecular masses of 68 and 73 kDa were expressed by bacteria grown in iron-chelate TSB.The pathogenicity was examined by intraperitoneal injection with live E. tarda grown under TSB, iron-chelate TSB and iron-supplemented TSB. The result of pathogenicity test showed significantly high mortality in the group of live E. tarda grown under iron-chelate TSB.The effect of formalin killed cell (FKC) of TSB cultured bacteria and 2,2'-dipyridyl FKC (DP-FKC) of cultured bacteria on the iron-chelate TSB on the development of protective immunity in olive flounder was studied. The level of immune response was evaluated with immunized fish at 1, 2, 3 and 4 weeks after immunization. The numbers of specific antibody secreting cells (SASCs) showed significantly increased level at 2 week after immunization in each group. The agglutination titre of immunized fish was significantly high level at 3 weeks after immunization.The level of protection in olive flounder at 1, 2, 3 and 4 weeks after vaccination was examined by intraperitoneal challenge test with live E. tarda.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.75-82
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• 2003

The cellular responses of RDX-degrading bacterium, Pseudomonas sp. HK-6 to explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) were examined. Strain HK-6 grown at different RDX concentrations was found to demonstrate the survival rate in proportional to the rate of the stress shock proteins produced in this bacterium. Analysis of total cellular fatty acid acids showed that lipids 10:0 iso and 14:1 $\omega$5c/$\omega$5t increased approx three times in strain HK-6 grown on RDX media than TSA media. SDS-PAGE and Western blot using anti-DnaK and GroEL revealed that several stress shock proteins including 70 kDa DnaK and 60 kDa CroEL were newly synthesized in strain HK-6 exposed to different RDX concentrations in exponentially growing cultures. 2-D PAGE of soluble protein fractions from the culture of HK-6 exposed to RDX demonstrated that approximately 300 spots were observed on the silver stained gel ranging from pH 3 to pH 10. As a result, 10 spots were significantly induced and expressed in response to RDX. Scanning electron microscopy fur the cells treated with 0.135 mM RDX for 12 hrs showed the presence of perforations and irregular rod shapes with wrinkled surfaces.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.556-562
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• 1999

The increasing price of surimi has affected the economical benefits of surimi based food industry, To maintain gel strength in low grade surimi, the optimum formulation adding functional proteins to low grade surimi is required. The objective of this study was to develop the optimum formulation of ingredients in making gels in low grade surimi on the addition of functional non-muscle proteins to low grade surmi by measuring rheological properties of the gels. The rheological qualities of the cooked gels made with A and RA grade surimi on the effects of adding five kinds of starches (potato, wheat, waxy maize, corn and modified corn) and four kinds of functional proteins (bovine plasma protein, dehydrated egg white, soy protein isolate and whey protein concentrate) to the gels were evaluated, The gel styengths at cooking with A and RA grade surimi were decreased with increasing the added starches. The kind of starches added affected little the gel strengths in Rh grade surimi, while potato and corn starches decreased at the least in gel strengths of the gel made with A grade surimi with increasing the concentration of starches. The bovine plasma protein (BPP) significantly increased the gel strength, especially in RA grade surimi, but BPP decreased the whiteness of the gel. Therefore, the optimum content of BPP was up to $2\%$ because of the whiteness of the gels in RA grade surimi, The optimum formulation for the gel with RA grade surimi to satisfy the gel strength of 1000$\times$g and $78\%$ moisture was $40.9\%$ surimi, $9.1\%$ dehydrated egg white (DEW) and $0.9\%$ starch, while that with A grade surimi under the same condition was $37.9\%$ surimi, $6.6\%$ DEW and $3,4\%$ starch.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.69-80
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• 2010

Hypocholesterolemic effect of soy protein was examined in comparison with casein and three other dietary protein sources in chicks. In two feeding trials, 40 (Expt.1) or 50 (Expt. 2), three-day-old, male chicks were forced-fed each of five semi-purified-type diets containing isolated soy protein (ISP, cp 82%), casein (cp 92%), rice protein (RP, cp 70%), corn gluten meal (CGM, cp 65%) or fish meal (FM, cp 70%) for two weeks. The diets for Expt. 2 were supplemented with 0.3% cholesterol by replacing glucose. Each protein source was the only source of protein of each diet. Essential amino acids were added to the diets to satisfy their requirements according to NRC. The diets were forced-fed to equalize the intake of all nutrients except the amino acids which were inherently variable in the diets. Chicks fed casein showed lower body weight gain than those fed the other proteins in both experiments. Birds fed ISP and FM gained better body weight than the others. Chicks fed casein showed significantly higher levels of plasma total cholesterol, non-HDL cholesterol and triacylglycerol (TG) than those fed ISP and the other protein sources. Meanwhile, the chicks fed ISP, RP, CGM and FM showed comparable levels of plasma total cholesterol, non-HDL cholesterol and TG. In Expt. 2, the birds fed casein and FM showed markedly elevated plasma total cholesterol and non-HDL cholesterol levels. Liver weight and levels of total lipids and cholesterol of chicks fed casein appeared significantly higher than those of the other protein diets, whereas those of the chicks fed ISP, RP, CGM and FM appeared comparable except cholesterol in FM group. In conclusion, only the chicks fed casein diets in both experiments always showed significantly higher levels of plasma cholesterol and TG compared to those fed ISP and the other protein sources. These results support the views that casein, which has unique lysine-arginine ratio, is inherently hyper-cholesterolemic, and ISP is hypocholesterolemic only when compared to casein.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.267-272
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• 1996

Effect of freezing of soybeans on instrumental and sensory textures of soybean curd was investigated. The hardness, gumminess and chewiness of soybean curd prepared with frozen soybeans were about three times as high as those prepared with unfrozen soybeans, while cohesiveness and elasticity were affected little by freezing. Sensory evaluation showed that freezing improved the quality of soybean curd. Instrumental and sensory textures of soybean curd prepared with frozen soybeans were excellent and almost same regardless of the boiling time when the soy slurry was boiled for 2.5 min or 5 min. However, the textures of soybean curd prepared with unfrozen soybeans were deteriorated by reducing the boiling time to 2.5 min. It was postulated that freezing facilitate the heat-denaturation of soyprotein to enhance aggregation of soy proteins and formation of cross-linkage between aggregate and $Ca^{++}$. Frozen soybeans resulted in soybean curd which lower fat content, while protein content of soybean curd was almost he same. Frozen soybeans gave a lower yield of soybean curd, which is supposed to be caused by the more fat loss during whey-off.